Given a unit sphere (r=1) that is to be viewed orthographically from (x:1, y:0, z:0), how can I calculate the 3D vector point on surface for any given 2D coordinate?
Let's say I have a 100x100 pixels image of an orthographic unit sphere, viewed from (1,0,0), how can I find out which 3D coordinate is at pixel (x:40, y:40)? I've tried using this inverse formula on wiki, but the results seems skewed: (disregard red line and the off-center crosshair marker).
(we've attempted to loop through every pixel in an x*y 2D picture and deducing the vector, but the "equator" is completely stretched. Every point on the equator seem to be the same point somehow)
